Foldable hydrofoil



KEITARO TAKAGI Aug. 17, 1965 FOLDABLE HYDROFOIL 4 Sheets-Sheet 1 FiledApril 23, 1963 INVENTOR- KEITARO TAKAGI ATTORNEYS z- 7, 1965 KEITAROTAKAGI 3,200,781

FOLDABLE HYDROFOIL Filed April 23, 1963 4 Sheets-Sheet 2 INVENTOR.KEITARO TAKAGI ATTORNEYS A 7, 1965 KEITARO TAKAGl 00,78

FOLDABLE HYDROFOIL Filed April 23, 1963 4 Sheets-Sheet 3 FIG. 3

INVENTOR. KEITARO TAKAGI ATTORNEYS Aug. 17, 1965 KElTARO TAKAGI 3,200,

FOLDABLE HYDROFOIL Filed April 23, 1963 4 Sheets-Sheet 4 INVENTOR.KEITARO TAKAGI ATTORNEYS United States Patent use 3,2dih75fi FSLDABLEHYDR OFGHL Keitaro Talragi, Setagaya-hu, Tokyo-to, Japan, assignor toIshikawajima-Harima .llnitogyo Kahushiiri Kaisha, Tokyo-to, Japan, acompany of Japan Filed Apr. 23, 1963, der. No. 275,168 Claims priority,application Japan, Apr. 30, 1962, 37/16,88 6 Claims. (Ci. lidefi) Thepresent invention relates to a hydrofoil for boats, and moreparticularly to a hydrofoil which is capable of being folded up.

A conventionally known hydrofoil is so constructed that the liftingfoil, the supporting foil, the strut, and other parts of the hydrofoilare fixed to each other, and when it is necessary to stow the hydrofoilaway, the lifting foil, the supporting foil and the strut are either tobe rotated about the point at which they are fitted to the hull, or tobe shifted upwardly alongside the hull, in order to be stowed away onthe deck or alongside the broadside of the boat.

In these cases, some serious drawbacks are inevitable: a larger space isnecessary for stowing away the hydrofoil. For example, when it is to bestowed away on the deck, it will be a hindrance in the use of the deck,and when it is stowed away alongside the broadside of the boat, thehydrofoil will not safe, as it protrudes far beyond the side of the boatwhen the boat docks at a pier or is running or is moored alongside othervessels.

The present invention aims to eliminate such defects as mentioned above.The main features of the invention are that the lifting foil, thesupporting foil, and the strut are not fixed as formerly but areconnected with each other by hinge joints; also the middle point of theabovementioned lifting foil, the supporting foil, and the strut areprovided with hinge joints, respectively, so that the hydrofoil can befolded up when it is stowed away.

Referring now to the drawings:

FIG. 1 shows the hydrofoil boat of the invention in a side view with thehydrofoil shown in its collapsed position stowed alongside of the bullin solid lines, and the hydrofoil is shown in its expanded, operativeposition in dot-dash lines;

FIG. 2 is a view of the hydrofoil taken from the left of FIG. 1 showingthe hydrofoil of the invention in its expanded, operative position withparts of the hull shown schematically;

FIG. 2 shows the structure of FIG. 2 in its collapsed position;

FIG. 3 is a plan view of the hydrofoil of the invention in its stowedposition, FIG. 3 also showing in dot-dash lines the expanded hydrofoilin its operative position;

FIG. 3 shows the stowed hydrofoil of FIG. 3 as it appears from thebottom of FIG. 3 looking upwardly, which is to say from the bow of thevessel looking toward the stern thereof, so that what is seen in FIG. 3is the front end of the stowed hydrofoil of the invention;

FIG. 4 is a view showing in an enlarged fragmentary section the mannerin which the hydrofoil is supported by the hull as well as the detailsof a structure for adjusting the angle of attack of the hydrofoil;

PEG. 4' shows part of the structure of FIG. 4 as seen from the left ofFIG. 4 to further illustrate the details of structure for adjusting theangle of attack;

FIG. 5 is a schematic diagram of the hydraulic circuit for controllingany one of the lock pins; and

FIG. 6 is a schematic illustration of the structure for driving thetorque generators.

As shown in the various views, a lifting foil 1, a supporting foil 2 anda strut 3 are freely connected with each djfidjldl Patented Aug. 17,1965 other by hinge joints 4, 5, respectively. In this exemplaryembodiment, the supporting foil is also capable of being folded at itsmiddle by means of a hinge joint 6.

It will, of course, be understood that instead of the supporting foil 2,either the lifting foil 1 or the strut 3, or all of the aforementionedelements, may be provided with hinge joints so that they may be folded.in half.

In the drawings, numeral 7 denotes a torque generator for folding andunfolding the. hydrofoil. The hydrofoil folded by the drive of thegenerator 7 is then to be stowed away in the given position on thebroadside 9 of the boat by the drive of another torque-generator 8 forrotating the foil, as is shown in solid lines FIG. 1 through FIG. 3,while the foil unfolded by the drive of the generator 7 is then to bepulled out for use by the drive of the generator 3, as is shown inbroken lines in the same figures.

The foil is kept secure in proper form for use by a locking pin it) ofthe supporting foil 2, the elevation of the foil 2 being kept constantby a locking pin 11 of the strut 3, and the regulation of the elevationbeing possible by moving fore and aft said locking pin.

When being stowed away, the foil is pulled up to the given position onthe broadside of the boat, and the folded foil is fixed to its positionby a stowing-away pin 12 and is protected by a platform 13, and,therefore, the possibility for the foil to be damaged is eliminated whenthe boat docks at the pier or stops alongside other vessels. At 13, adownwardly directed lateral flange of the platform 13 is shown, while1?)" denotes a bracket for fixing the flange la.

The hydrofoil of the invention includes the lifting foil 1 and thesupporting foil which includes an upper sec tion 2 and a lower section 2which are hingedly c0nnected to each other by the hinge 6. The strut 3is sup ported for turning movement by the side of the hull, this strut 3being supported for turning movement about an axis which extendstransversely across the hull, and the lifting foil 1 is connected by ahinge d to a bottom end of the strut 3 which extends in a generally upand down direction when it is in its operating position. The uppersection 2 of the supporting foil is hinged by a hinge 7 to the upper endof the strut 3 and, of course, this end of the strut 3 becomes theforward end thereof when the strut 3 is turned to its horizontal, stowedposition.

A releasable lock means, which includes the pin it is carried by thesection 2 and is capable of extending through an opening at the upperend of the section 2" for releasably locking the sections 2 and 2' intheir expanded position where they are located in a common plane (FIG.2), and in a manner described below, the pin 10 can be retracted torelease the sections 2 and 2' for movement to their collapsed position.The strut 3 has a laterally projecting shaft portion 14 which issupported for turning movement in a bearing 15, the axis of the shaft 14and bearing 15 extending transversely across the hull.

The strut 3 is formed with a bore which is capable of receiving thelocking pin 11 which forms part of a second releasable lock means forreleasably locking the strut 3 in its operative position, and in orderto be able to adjust the angle of attack the bearing 15 supports forrotation a lever 16 which carries a cylinder 11' in which a piston atthe inner end of the cylinder 11' is capable of sliding.

As is shown most clearly in FIGS. 4 and 4, the lever 16, which can swingaround the bearing 15, carries a stud 17 which extends through a slot i9formed in a wall 9' of the hull, this slot 19 extending along a circlewhose center is in the axis of the shaft 14, and the stud 17 carries apair of nuts 18 which can be loosened for adjusting the angular positionof the releasable lock pin ll which also extends at the outer wall 9 ofthe hull through a slot identical with and aligned with the slot 19shown in FIG. 4'.

When the position of the pin 11 is adjusted the nuts 18 are tightenedwith one of the nuts engaging the hull wall 9' and the other engagingthe first nut so that in this way a lock-nut assembly is provided forretaining the pin 11 in its adjusted position, and when the strut 13 isturned to its operating position it will receive in its bore the pin 11,so as to be releasably retained in an adjusted operating position whereit extends in a generally up and down direction.

As may be seen from FIG. 6, the torque generator 7 includes a cylinder'70, and this cylinder is rigidly fixed with the strut 3, and within thecylinder is a rotary shaft 7b which is supported for turning movement bythe end walls of the cylinder and which extends fluid-tightly throughone of these walls to be fixed rigidly with one end of the supportingfoil section 2, so that the hinge 7 is actually an integral extension ofthe shaft 7b within the cylinder 7a and is rigidly fixed with thesupporting foil section 2 so that the latter will turn with the shaft '7b.

The torque generator 8 is identical with the torque generator 7 and isrigidly fixed to the side of the hull, which is to say a cylinder 8a ofthe torque generator 8 is rigidly fixed to the side of the hull, and inthis case a shaft 8!) is supported for rotary movement by the cylinderand projects fiuid tightly therefrom to the shaft 14 to which it iscoaxially fixed so that the shaft 14 is necessarily constrained to turnthe shaft 8b of the torque generator 8.

There is shown in the drawings an eye 2t fixedly carried by the strutand capable of receiving the lock pin 16 when the hydrofoil is in itscollapsed position so that in this way the structure can be retained inits collapsed position. When the hydrofoil, after collapse thereof, hasbeen turned to its stowed position the bore of the strut 3 will receivethe lock pin 12 so that in this Way the structure will be retained inits stowed position.

As was indicated above, all of the lock pins ill-12 are .of an identicalconstruction and are actuated with precisely the same structure, .and anexample of this structure is shown in FIG. 5 where it will be seen thatthe lock pins 1042 are respectively located within the cylinders Ely-12'(of which it has been mentioned above in connection with lever 16).Selector valves 1tl"l2" are hydraulically connected with the cylinders10 2', respectively, so that by suitable manual control of these valvesit is possible to displace the lock pins 10-12 either 'to a retractedinoperative position or to a projecting operative position.

The adjustment of the angle of attack has been described above.

Referring to FIG. 6, the torque generators 7 and 8 each include, inaddition to their cylinders 7a, 8a and shafts 7b and 8b, a vane 7d, 8drespectively fixed to and projecting laterally from the shaft 711, 8b.The length of this vane corresponds to the length of the cylinder andits outer edge is located close to the inner surface of the cylinder,and it will be noted that there is within each cylinder a portion 70, 80so that the selector valves '7", 8 can be actuated to introduce fluidunder pressure into each cylinder at either side of the vane 7d or 8d soas to turn the shaft '71) or 82) in a selected direction. Thus it ispossible to collapse or expand the hydrofoil with the torque generator 7and to turn the entire hydrofoil between its substantially horizontalstowed position and its operating position where it extends in agenerally up and down direction.

In the case of FIGS. 5 and 6, the source of power is derived from anengine 21 through a clutch 22 which transmits the drive from the engine,when the clutch is engaged, to a pump 23 which circulates the liquid inthe manner shown diagrammatically in FIGS. 5 and 6, so that through theactuation of the valves it is possible to selectively operate the lockpins or the torque generators, and the liquid is taken by the pump 23from a tank 24 to which the liquid is returned with the liquid flowingthrough a strainer, as diagrammatically indicated. Thus, the operatorcan at any time selectively actuate any of the lock pins or the torquegenerators to displace the hydrofoil between dits expanded and collapsedpositions as well as between its stowed and operative positions Forfurther clarification of the schematic hydraulic diagrams appearing inFIGS. 5 and 6, the operation of the selector valve ltll2" will bedescribed in connection with the locking pins ltY-IZ (FIG. 5), as wellas that of the valves '7", 3 with respect to the torque generators 7, 8(FIG. 6).

In FIGS. 5 and 6, the valves are shown with three types of symbols intheir lower, upper and intermediate sections, the latter correspondingto the rest or neutral positions. The lower section (active when thevalves are pushed upward) indicates continuous through-flow between theconduits on the leftand right-hand sides of the valves, in thedirections identified by the arrows. The upper section (operative whenthe valves are pushed downward) shows crossed arrows, denoting that theupper and lower conduits coming from the left-hand side are connectedcrosswise with the lower and upper conduits of the right-hand side,respectively. Finally, the intermediate or neutral section shows areturn path allowing the oil coming from pump 23 to flow back to thetank 24.

FlG. 5 shows the neutral positions of valves 10-12", wherein no oilreaches the respective locking pins 10'-12'-. The pistons of these pins.are, therefore, fixed in any desired position. If the selector valvesare pushed upward, the oil supplied by the pump 23 flows toward theleft-hand side chamber of the locking pins (in the upper conduit), so asto displace the pistons in outward direction. If, however, the selectorvalves are pushed downward, the oil will flow in the opposite direction,that is toward the right-hand side chamber (in the lower conduit), sothat the pistons are pushed back against the biasing springs.

FIG. 6, in a similar manner, shows the neutral positions of valves 7",8", wherein no oil is supplied to the respective torque generators 7, 8.The shafts 7b, 8b and the vanes 7d, 8d, are, therefore, fixed at anydesired position. If the selector valves are pushed upward, the oil willenter the left-hand inlet of the generators, through the upper conduit,so as to move the vanes in clockwise direction, as shown in FIG. 6. If,on the other hand, the valves are pushed downward, the oil will fiowtoward the right-hand side generator inlet, through the lower conduit,whereby the vanes are moved in counterclockwise direction.

As will be understood from the foregoing detailed description, thepresent invention provides various excellent features, namely: as thehydrofoil can be folded up properly when stowed away, the necessaryspace can be much small-er than needed by conventional type hydrofoils;also, there will be no inconvenience in the use of the deck, as thehydrofoil can be stowed away below deck side level and above water line;furthermore, the hydrofoil can be protected completely, even at the timeof docking or stopping alongside other vessels, by constructing aplatform for protecting the foil and the broadside of the boat over theplace where the hydrofoil is stowed away so that it may constitute apart of the deck.

The foregoing description and the exemplary embodiment illustratedrelate to a case wherein the present invention is applied to the forwardhydrofoil assembly of the surface piercing split type, but it isunderstood that the present invention can be applied to hydrofoils ofother type as well. In either of these cases, the component parts cantake forms or styles which are different from those shown in thedescribed example, though, of course, within the limits of technicalfeasibility and the scope of the invention as set forth in the appendedclaims.

What I claim is:

1. A hydrofoil boat comprising an elongated hull having a side, ahydrofoil located at the side of the hull and including an elongatedsubstantially rigid strut having an operative position extending in agenerally up and down direction and located directly next to said sideof said hull, said hydrofoil further including a lifting foil hingedlyconnected to a bottom end of said strut and a supporting foil having apair of sections hingedly connected to each other with one of saidsections hinged to an upper end of said strut and with the other sectionhinged to an end of said lifting foil distant from said strut, turningmeans operatively connected to the supporting foil section which ishinged to said strut for turning the latter section of said supportingfoil away from said strut so as to locate said sections of saidsupporting foil in a common plane and place the hydrofoil in an expandedposition where the supporting foil, the lifting foil, and the strut,respectively, extend substantially along the sides of a triangle, saidturning means also being connected to the section of said supportingfoil which is connected to said strut for turning the latter section ofsaid supporting foil to a collapsed position next to said strut, and thesupporting foil section which is connected to said lifting foilautomatically b.- corning located alongside of the section which is connected to said strut to displace said lifting foil to a collapsedposition extending generally parallel to said strut and located adjacentthereto with the collapsed supporting foil situated between said strutand said lifting foil, and support means supporting said strut on saidside of said hull for turning movement, about an axis extendingtransversely across the hull, from a position where said strut extendsin a generally up and down direction to a stowed position where saidstrut and the collapsed supporting foil and lifting foil all extend in agenerally horizontal direc tion and are located closely adjacent to theside of the hull.

2. A boat as recited in claim 1 and wherein one of said sections of saidsupporting foil carries a releasable lock means for releasably lockingsaid supporting foil in its expanded position where the sections thereofare located in a common plane.

3. A boat as recited in claim 1 and wherein a releasable lock means iscarried by the hull and cooperated with said strut for releasablymaintaining the latter in said operative position where it extends in agenerally up and down direction.

4. A boat as recited in claim 1 and wherein an elongated platform iscarried by and projects from said side of said hull and is situated overand covers the hydrofoil when the latter is in said stowed position, forprotecting the stowed hydrofoil.

5. A boat as recited in claim 4 and wherein said platform has at adistance from the side of said hull a downwardly directed side flangewhich extends alongside of the hydrofoil when the latter is in saidstowed position thereof to protect the stowed hydrofoil from beingdamaged by docks or other vessels located alongside of said side of saidhull.

6. A boat as recited in claim 1 and wherein a means is carried by thehull and is operatively connected to said strut for turning the latterabout said transverse axis to displace the hydrofoil between said stowedposition thereof and an operating position where said strut is in itsoperative position and the supporting and lifting foils are capable ofbeing displaced laterally away from said strut to their expandedpositions.

References Cited by the Examiner UNITED STATES PATENTS 1,750,959 3/30Lake 114-4365 2,108,574 2/38 Atwell 1l4-126 2,887,979 5/59 Bader 1l466.52,906,229 9/59 Boericke 114-665 2,991,747 7/61 Bader et al. ll466.53,099,239 7/63 Von Schertel et a1. l14-66.5

FOREIGN PATENTS 582,985 12/46 Great Britain. 1,066,897 1 10/59 Germany.

FERGUS S. MIDDLETON, Primary Examiner.

MILTON BUCHLER, Examiner.

1. A HYDROFOIL BOAT COMPRISING AN ELONGATED HULL HAVING A SIDE, AHYDROFOIL LOCATED AT THE SIDE OF THE HULL AND INCLUDING AN ELONGATEDSUBSTANTIALLY RIGID STRUT HAVING AN OPERATIVE POSITION EXTENDING IN AGENERALLY UP AND DOWN DIRECTRION AND LOCATED DIRECTLY NEXT TO SAID SIDEOF SAID HULL, SAID HYDROFOIL FURTHER INCLUDING A LIFTING FOIL HINGEDLYCONNECTED TO A BOTTOM END OF SAID STRUT AND A SUPPORTING FOIL HAVING APAIR O/F SECTIONS HINGEDLY CONNECTED TO EACH OTHER WITH ONE OF SAIDSECTIONS HINGED TO AN UPPER END OF SAID STRUT AND WITH THE OTHER SECTIONHINGED TO AN END OF SAID LIFTING FOIL DISTANT FROM SAID STRUT, TURNINGMEANS OPERATIVELY CONNECTED TO THE SUPPORTING FOIL SECTION WHICH ISHINGED TO SAID STRUT FOR TURNING THE LATTER SECTION OF SAID SUPPORTINGFOIL AWAY FROM SAID STRUT SO AS TO LOCATE SAID SECTIONS OF SAIDSUPPORTING FOIL IN A COMMON PLANE AND PLACE THE HYDROFOIL IN AN EXPANDEDPOSITION WHERE THE SUPPORTING FOIL, THE LIFTING FOIL, AND THE STRUT,RESPECTIVELY, EXTEND SUBSTANTIALLY ALONG THE SIDES OF A TRIANGLE, SAIDTURNING MEANS ALSO BEING CONNECTED TO THE SECTION OF SAID SUPPORTINGFOIL WHICH IS CONNECTED TO SAID STRUT FOR TURNING THE LATTER SECTION OFSAID SUPPORTING FOIL TO A COLLAPSED POSITION NEXT TO SAID STRUT, AND THESUPPORTING FOIL SECTION WHCIH IS CONNECTED TO SAID LIFTING FOILAUTOMATICALLY BECOMING LOCATED ALONGSIDE OF THE SECTION WHICH ISCONNECTED TO SAID STRUT TO DISPLACE SAID LIFTING FOIL TO A COLLAPSEDPOSITION EXTENDING GENERALLY PARALLEL TO SAID STRUT AND LOCATED ADJACENTTHERETO WITH THE COLLAPSED SUPPORTING FOIL SITUATED BETWEEN SAID STRUTAND SAID LIFTING FOIL, AND SUPPORT MEANS SUPPORTING SAID STRUT ON SAIDSIDE OF SAID HULL FOR TURNING MOVEMENT, ABOUT AN AXIS EXTENDINGTRANSVERSELY ACROSS THE HULL, FROM A POSITION WHERE SAID STRUT EXTENDSIN A GENERALLY UP AND DOWN DIRECTION TO A STOWED POSITION WHERE SAIDSTRUT AND THE COLLAPSED SUPPORTING FOIL AND LIFTING FOIL ALL EXTEND IN AGENERALLY HORIZONTAL DIRECTION AND ARE LOCATED CLOSELY ADJACENT TO THESIDE OF THE HULL.